Repairing clutch

[dirty tools]

I am trying to repair my 13” South Bend lathe clutch
no parts are available due to the age (1916) “O” series apron
I have tried many upgrade to a newer series clutch, the problem is with the O.D. Of the clutch assy about 3/16 to large of Diameter.
you just can’t cut it to the correct diameter because you is a gear.
I have modified the shaft to fit .
on the bench it works great, I can’t mount it due today the gear diameter

I had the original gear (worn out) TIG welded
horrible looking
to day I manage to make a jig to mount it in the lathe chuck
managed to get it turned to the correct O.D.
next is to cut the gears, they are acme threads , any suggestions
pan

 

[Jim F]

Like it was made, grind a HSS cutter.

 

[benmychree]

Worm threads are not Acme threads, they are worm threads, gages are made to grind the tools, question might be are they TPI or Diametral Pitch.